HIV+ Alveolar Macrophage Oxidant-mediated Apoptosis of Pulmonary Endothelium

描述(由申请人提供)：尽管使用高效抗逆转录病毒疗法(HAART)提高了艾滋病毒(HIV)感染者的存活率，但艾滋病毒感染者患慢性阻塞性肺疾病(表现为肺气肿)的风险增加。与吸烟者相比，肺气肿发生的年龄更早，并被认为是接受HAART治疗的HIV+人群发病率增加的一个原因。HIV相关肺气肿的发病机制被认为是由于下呼吸道炎症细胞衍生蛋白和/或氧化剂的过度负荷、HIV蛋白的直接作用或抗逆转录病毒治疗的不良反应所致。尽管有证据支持这些机制中的每一种，但在人类身上指向特定分子靶点的数据有限，这些分子靶标有助于破坏下呼吸道导致肺气肿。基于HIV+个体产生的初步数据，我们将使用多学科方法来探索这一假设，即HIV感染和吸烟的组合激活了肺泡巨噬细胞(AM)，在下呼吸道产生慢性氧化应激，促进肺毛细血管内皮细胞的凋亡，促进进行性肺泡破坏。我们将通过支气管肺泡灌洗对HIV+和HIV受试者进行AM和下呼吸道上皮衬底液(ELF)采样，并评估血浆肺毛细血管内皮细胞微粒(EMPs)作为持续肺毛细血管内皮细胞凋亡的生物标志物来研究这一假说。使用新开发的质谱学方法，我们将量化AM、ELF和血浆EMPs的氧化应激，并识别这些隔室中特定的氧化代谢物。最后，我们将在体外模拟AM-肺毛细血管内皮细胞的相互作用，以梳理出相互作用的各个组成部分的贡献。我们将使用3个具体目标评估HIV+和HIV-非吸烟者、吸烟者、早期吸烟者和有肺气肿黄金标准的吸烟者。目的1.通过评估AM自发产生的氧化剂，结合质谱学评估AM和下呼吸道ELF的氧化状态，探讨HIV+和HIV感染者下呼吸道的氧化应激程度。目的2.检测HIV阳性非吸烟者和吸烟者血浆中肺毛细血管细胞凋亡衍生的EMPs水平，并评价这些EMPs各组分的氧化状态。目的3.以细胞凋亡和内皮代谢产物的氧化状态为表型，研究HIV+和HIV-患者肺毛细血管内皮细胞与AM的相互作用。随着我们开发数据来巩固我们的假设，我们预计会发现一类新的靶点，以测试旨在预防艾滋病毒相关肺气肿的药物。

DESCRIPTION (provided by applicant): Despite the increased survival of individuals with HIV-1 (HIV) infection resulting from the use of highly active antiretroviral therapy (HAART), individuals infected with HIV have an increased risk for the development of chronic obstructive pulmonary disease, manifesting as emphysema. The emphysema occurs at an earlier age than in HIV- smokers, and is recognized as an increasing cause of morbidity in the HAART-treated HIV+ population. The pathogenesis of HIV-associated emphysema has been hypothesized to result from an exaggerated lower respiratory tract burden of inflammatory cell-derived proteases and/or oxidants, direct effects of HIV proteins, or adverse effects of anti- retroviral therapy. Despite evidence to support each of these mechanisms, there is limited data in humans pointing to specific molecular targets that contribute to the destruction of the lower respiratory tract leading to emphysema. Based on preliminary data generated from HIV+ individuals, we will use a multidisciplinary approach to explore the hypothesis that the combination of HIV infection and smoking activates alveolar macrophages (AM) to create chronic oxidant stress in the lower respiratory tract that promotes apoptosis of the pulmonary capillary endothelium, contributing to progressive alveolar destruction. We will study this hypothesis by sampling HIV+ and HIV- subjects for AM and lower respiratory tract epithelial lining fluid (ELF) by bronchoalveolar lavage, and by assessing plasma pulmonary capillary-derived endothelial microparticles (EMPs) as a biomarker for ongoing pulmonary capillary endothelial apoptosis. Using newly developed mass spectrometry methodologies, we will quantify the oxidant stress of AM, ELF and plasma EMPs, and identify specific oxidized metabolites within each of these compartments. Finally, we will model the AM-pulmonary capillary endothelial interaction in vitro to tease apart the contribution of each component of the interaction. We will assess HIV+ and HIV- nonsmokers, smokers, smokers with early and GOLD criteria emphysema using 3 specific aims. Aim 1. To explore the extent of oxidant stress in the lower respiratory tract of HIV+ and HIV- subjects by assessing spontaneous AM generation of oxidants, together with mass spectrometry-based assessment of the oxidation state of AM and lower respiratory tract ELF. Aim 2. To evaluate the plasma levels of pulmonary capillary apoptosis-derived EMPs of HIV+ nonsmokers and smokers, and to assess the oxidation state of the components of these EMPs. Aim 3. To examine the interaction of pulmonary capillary endothelium with AM of HIV+ and HIV- subjects, using apoptosis and the oxidation state of endothelial metabolites as the phenotype of the interaction. As we develop data to solidify our hypothesis, we expect to uncover a new class of targets to test drugs aimed at preventing HIV-associated emphysema.